General Motors is likely to follow Chrysler and make a quick sale of its best assets to a new operating company if it files for bankruptcy on 1 June, the automaker has said in a regulatory filing.

The disclosure to the US Securities and Exchange Commission (SEC) was the first time that GM had said it would most likely pursue the same legal strategy that Chrysler was using under federal oversight to slash its debt and dealerships, Reuters noted.

GM has until 1 June to restructure its bond debt and reach a wide-ranging new agreement with the UAW; the Wall Street Journal today said agreement was close.

The automaker repeated in its SEC filing that it expected to file for bankruptcy if not enough of its bonds were tendered in exchange for shares by the deadline, Reuters said.

As part of the restructuring now headed by CEO Fritz Henderson, GM has had legal advisers mapping out a strategy if it is forced to file for bankruptcy, the report added.

GM has said that those options could include a sale of its profitable assets under Section 363 of the bankruptcy code.

"We are considering ... alternatives in consultation with the US Department of the Treasury, our largest lender," GM said in the filing. "We currently believe that if we pursue one of these [bankruptcy] alternatives, a 363(b) sale would be the most likely."

Reuters noted that Chrysler, which filed for bankruptcy protection on 30 April after failing to win a deal with secured lenders to cut its debt, aims to use that provision of the bankruptcy code to complete an alliance with Fiat later this month.

That planned alliance has now received US Federal Trade Commission clearance after the regulator ruled there were no competitive issues.

It was not immediately clear what entity would buy GM assets out of bankruptcy, but analysts have told Reuters an entity backed by the US government was one likely alternative.

Obama administration auto task force officials have described Chrysler's strategy as a "quick rinse" or a "surgical" bankruptcy intended to allow the automaker to resume operations quickly and minimise uncertainty for consumers.

But the process has also proved controversial because of the administration's insistence that the UAW have its unsecured claims against Chrysler paid out at a higher rate than the recovery for the higher-ranking secured debt, Reuters noted.

Analysts have said similar disputes between creditors could complicate any GM restructuring under court protection.

GM has offered to swap US$27.1bn of bond debt for a 10% stake in a restructured company under the majority ownership of the US Treasury.

The automaker has also said it needs to to swap out of 90% of the value of the debt they are owed in order to avoid a bankruptcy filing.

The report added that GM remains in talks with the UAW on a new contract and new payment terms for the $20bn it owes the union for retiree health care.

The union, which could own almost 40% of the restructured GM through a retiree trust fund, has objected to the automaker's plans to import more vehicles into the US market at the same time it is looking to cut about 21,000 additional US factory jobs, Reuters added.